Zygomatic Approach Research Articles

Zygomatic approach with single-piece implants: A technical note.

Single piece zygomatic implant, or a remote anchorage implant, is an effective tool for the rehabilitation of the atrophic/resected jaws with least postoperative complications such as screw loosening, screw fractures, bone loss, mucositis, and peri implantitis. The aim of this paper was to summarize a technique for the use of a zygomatic approach for single piece implants. We used the key-words 'single piece implants” and the search revealed 700 papers in the PubMed database. After screening through the abstracts, we selected 50 articles that we finally reviewed. Zygomatic fixtures avoid the grafting procedures and cantilever situation, restoration of atrophic or postablative jaws are completed with immediate loading. It is advisable placement of zygomatic implant flapless with surgical guide, but the author believes more on the tactile perception and when the splint is at mucosal or bone level, a small change in orientation will lead the dramatic error in desired angulation leading to unwanted complication.

The Utilization of the Cranio-Orbital Zygomatic Approach for the Resection of Juvenile Nasopharyngeal Angiofibroma: 2-Dimensional Operative Video.

Juvenile angiofibroma is a rare benign expansive lesion typically affecting young men. Surgery is the current mainstay of treatment. Because it is a very vascular lesion, preoperative transarterial embolization can decrease intraoperative bleeding.1,2 Transmaxillary or transpalatal approaches were used for totally extracranial lesions. Endonasal endoscopic resection became wildly used for radical excision with limited morbidity.2 In large lesions with intracranial extension and cavernous sinus involvement (Fisch type 4), purely anterior approaches (endoscopic or transmaxillary) can be associated with significant carotid artery and cranial nerves injuries and excessive hemorrhage from internal carotid artery supply that cannot be eliminated by preoperative embolization.3 Subtotal resection has been preconized in such cases, but tumor progression, cranial nerves and vision compromise, and major nasal postoperative bleeding could ensue. Radiotherapy of residual tumor has been associated with long-term complications, particularly given the young age of these patients.2 The cranio-orbital zygomatic approach provides an excellent exposure to the extensions into the middle fossa, anterior fossa, cavernous sinus, paranasal sinus, and infratemporal fossa components of large angiofibromas.4-6 It is particularly advantageous in the early interruption of the cavernous carotid feeders that are not amenable to safe embolization, rendering the tumor devascularized and bloodlessly resected. This article demonstrates the details and the advantages of this approach in a 13-year-old adolescent boy operated in 1997 for giant juvenile angiofibroma with extension in the middle fossa and the parasellar space with major vascularization from the cavernous carotid artery. The guardian consented to the procedure and publication of images. Image at 3:05 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, © LWW, 1998. Image at 3:25 from Arnautović KI, Al-Mefty O, Angtuaco E. A combined microsurgical skull-base and endovascular approach to giant and large paraclinoid aneurysms. Surg Neurol. 1998;50(6):504-520; © Elsevier, 1998. Used with permission. Image at 9:21 reprinted from Kempe LG and Krekorian EA,6 with permission from John Wiley and Sons, © 1969 The Triological Society.

Simpson Grade I Resection of Type II Clinoidal Meningioma Through Cranio-orbital Zygomatic Approach: 2-Dimensional Operative Video.

Clinoidal meningiomas have been considered as a separate entity with distinguishing clinical, radiological, and surgical considerations.1-2 Surgical mortality and morbidity associated with anterior clinoidal meningiomas has remained high in the past, with radical resection considered unattainable.3 However, the extent of surgical removal is clearly the most determining factor in tumor recurrence and progression. Clinoidal meningiomas have been classified into 3 types according to their origin from the dura surface of the anterior clinoid and subsequent arachnoidal rearrangement around the parasellar neurovascular structures.1 In type II, there is an arachnoidal plane that allows the tumor dissection from the encased carotid artery and its branches and the optic nerve. In this type, the involvement of the cavernous sinus is limited to the external wall, which can also be removed. Hence, these tumors are amenable to Simpson grade I resection (tumor, dura, and bone). Approaching through the multidirectional axis provided by the cranio-orbital zygomatic approach allows safe exposure of the tumor and vascular control.4-5 Proximal carotid control is obtained in the petrous carotid canal, the invaded anterior clinoid is removed by and large extradurally, and the Sylvian fissure is split wide open to establish dissecting planes with the middle cerebral artery branches. The optic canal is opened, and tumor extension is removed.6 The invaded outer wall of the cavernous sinus and superior orbital fissure is removed. We demonstrate this technique in a 48-yr-old patient who consented for surgery and publication of images. All images at 2:27, center and right images at 2:46, and all images at 2:58, reused with permission from LWW, from Al-Mefty, Operative Atlas of Meningiomas. Left image at 2:46 reprinted from Surg Neurol, Vol 60/issue 6, Arnautović KI, Al-Mefty O, Angtuaco E, A combined microsurgical skull-base and endovascular approach to giant and large paraclinoid aneurysms, pp. 504-520, Copyright 1998, with permission from Elsevier. Image at 8:21 reprinted from Al-Mefty,1 Clinoidal meningiomas, by permission from JNSPG.

Cervical to Petrous Carotid Artery High-Flow Bypass for Carotid Artery Pseudoaneurysm Through Zygomatic Approach: 2-Dimensional Operative Video

Pseudoaneurysms of the cervical internal carotid artery may generate grave risk from catastrophic rupture, thromboembolic stroke, or mass effect. They have many causes, including malignancy, infection, and iatrogenic and most commonly blunt or penetrating trauma.1 These aneurysms require treatment to eliminate their risk. Treatment options include trapping, with or without revascularization, or endovascular stenting. Trapping without revascularization requires evaluation of the cerebral collateral under a physiological challenge, which is usually done with a balloon occlusion test, which is not applicable in this lesion.2 Occluding the carotid without revascularization carries the risk of delayed ischemia and aneurysm formation.3,4 Carotid stenting has been applied in the treatment of these lesions5,6; however, the extent of the lesion in our patient from the carotid bifurcation to the petrous carotid makes endovascular treatment challenging. We present a patient with a delayed post-traumatic pseudoaneurysm of the carotid artery that extended from the bifurcation to the petrous carotid who was treated with trapping and high-flow saphenous vein bypass from the proximal cervical internal carotid to the petrous carotid. Adequate exposure of the petrous carotid to perform anastomosis requires a thorough knowledge of the anatomy and surgical nuances, which we demonstrate here through a zygomatic approach.7 The patient consented to the procedure and publication of imaging. Image at 2:28 from Al-Mefty O, Operative Atlas of Meningiomas, © LWW, 1997, with permission.

Aggressive Radiation-Induced Cavernous Sinus Meningioma: 2-Dimensional Operative Video.

Radiation-induced meningiomas are the most common radiation-induced neoplasms. They exhibit a distinct aggressive clinical behavior as rapid growth, recurrences, multiplicity, and malignant progression are common features.1-4 Atypical histological findings and aberrant cytogenetics are increasingly identified.5-7 Radical resection of aggressive radiation-induced meningiomas is the best treatment option and would offer the best chance for control of the disease. Wide bone and dural margins should be pursued in the resection. Parasellar extension creates significant surgical challenges. Cavernous sinus exploration through the multidirectional axis provided by the cranioorbital zygomatic approach allows radical resection of the tumor, cranial nerve decompression, and carotid artery preservation and control.8-11 This article describes a cavernous sinus radiation-induced meningioma after radiation for Cushing disease. It demonstrates the details of the extra- and intradural exploration and dissection of the neurovascular structures in the cavernous sinus, with proximal and distal control of the carotid artery. However, even after radical resection, recurrence is a common finding in this malignant behavioral radiation-induced tumor. Patient consented for surgery. Image at 9:41 comes from the Science Museum Group, United Kingdom. Refer to the Wellcome blog post (archive). This image is licensed under the CC-BY 4.0 International license.

Zygomatic Approach to Cavernous Sinus Chordoma: 2-Dimensional Operative Video.

Chordoma is not a benign disease. It grows invasively, has a high rate of local recurrence, metastasizes, and seeds in the surgical field.1 Thus, chordoma should be treated aggressively with radical resection that includes the soft tissue mass and the involved surrounding bone that contains islands of chordoma.2-5 High-dose radiation, commonly by proton beam therapy, is administered after gross total resection for long-term control. About half of chordoma cases occupy the cavernous sinus space and resecting this extension is crucial to obtain radical resection. Fortunately, the cavernous sinus proper extension is the easier part to remove and pre-existing cranial nerves deficit has good chance of recovery. As chordomas originate and are always present extradurally (prior to invading the dura), an extradural access to chordomas is the natural way for radical resection without brain manipulation. The zygomatic approach is key to the middle fossa, cavernous sinus, petrous apex, and infratemporal fossa; it minimizes the depth of field and is highly advantageous in chordoma located mainly lateral to the cavernous carotid artery.6-12 This article demonstrates the advantages of this approach, including the mobilization of the zygomatic arch alleviating temporal lobe retraction, the peeling of the middle fossa dura for exposure of the cavernous sinus, the safe dissection of the trigeminal and oculomotor nerves, and total control of the petrous and cavernous carotid artery. Tumor extensions to the sphenoid sinus, sella, petrous apex, and clivus can be removed. The patient is a 30-yr-old who consented for surgery.

Spheno-Orbital Meningioma with Cavernous Sinus Extension.

We present a case of a 37-year-old female, with progressive left eye proptosis and an extensive ipsilateral en plaque spheno-orbital meningioma, with diffuse involvement of the lateral wall of the cavernous sinus and the orbit.A cranio-orbital zygomatic approach was performed to reach all extension of the lesion. We made an extradural clinoidectomy and an extensive bone removal of the orbit, exposition of the superior and lateral walls of the cavernous sinus, unroofing of the optic canal, superior orbital fissure, foramen rotundum, and foramen ovale. We performed the peeling of the lateral wall of cavernous sinus with total removal and preservation of the cranial nerves anatomy and function.In this video, we illustrate the importance of the first time aggressive removal of such tumors. We also demonstrate the concept that secondary invasion of the cavernous sinus are suitable for removal with cranial nerve preservation. The link to the video can be found at https://youtu.be/GJmkqVa6jSs .

Use of endoscopic transorbital and endonasal approaches for 360° circumferential access to orbital tumors.

Orbital tumors are often surgically challenging because they require an extensive fronto-temporo-orbital zygomatic approach (FTOZ) and a multidisciplinary team approach to provide the best outcomes. Recently, minimally invasive endoscopic techniques via a transorbital superior eyelid approach (ETOA) or endoscopic endonasal approach (EEA) have been proposed as viable alternatives to transcranial approaches for orbital tumors. In this study, the authors investigated the feasibility of 360° circumferential access to orbital tumors via both ETOA and EEA. Between April 2014 and June 2019, 16 patients with orbital tumors underwent either ETOA or EEA at the authors' institution. Based on the neuro-topographic "four-zone model" of the orbit with its tumor epicenter around the optic nerve in the coronal plane, ETOA (n = 10, 62.5%) was performed for tumors located predominantly superolateral to the nerve and EEA (n = 6, 37.5%) for those located predominantly inferomedial to the nerve. Eight patients (50%) presented with intraconal tumors and 8 (50%) with extraconal ones. The orbital tumors included orbital schwannoma (n = 6), cavernous hemangioma (n = 2), olfactory groove meningioma (n = 1), sphenoorbital meningioma (n = 1), chondrosarcoma (n = 1), trigeminal schwannoma (n = 1), metastatic osteosarcoma (n = 1), mature cystic teratoma (n = 1), sebaceous carcinoma (n = 1), and ethmoid sinus osteoma (n = 1). The clinical outcomes and details of surgical techniques were reviewed. Gross-total resection was achieved in 12 patients (75%), near-total resection in 3 (18.8%), and subtotal resection in 1 (6.2%). Eight (88.9%) of the 9 patients with preoperative proptosis showed improvement after surgery, and 4 (66.7%) of the 6 patients with visual symptoms demonstrated improvement. Four (40%) of the 10 patients treated with ETOA experienced partial third nerve palsy immediately after surgery (3 transient and 1 persistent). There have been no postoperative CSF leaks or infections in this series. Without transcranial approaches requiring temporalis muscle dissection and orbitozygomatic osteotomy, the selection of ETOA or EEA based on a concept of a four-zone model with its epicenter around the optic nerve successfully provides a minimally invasive 360° circumferential access to the entire orbit with acceptable morbidity.

ORIS Criteria of Success for the Zygoma-Related Rehabilitation: The (Revisited) Zygoma Success Code.

Zygomatic-related implant rehabilitation differs from traditional implant treatment in biomechanics, clinical procedures, outcomes, and eventual complications such as soft tissue incompetence or recession that may lead to recurrent sinus/soft tissue complications. The extreme maxillary atrophy that indicates the use of zygomatic implants prevents use of conventional criteria to describe implant success/failure. Currently, results and complications of zygomatic implants reported in the literature are inconsistent and lack a standardized systematic review. Moreover, protocols for the rehabilitation of the atrophic maxilla using zygomatic implants have been in continuous evolution. The current zygomatic approach is relatively new, especially if the head of the zygomatic implant is located in an extramaxillary area with interrupted alveolar bone around its perimeter. Specific criteria to describe success/survival of zygomatic implants are necessary, both to write and to read scientific literature related to zygomatic implant-based oral rehabilitations. The aim of this article was to review the criteria of success used for traditional and zygomatic implants and to propose a revisited Zygomatic Success Code describing specific criteria to score the outcome of a rehabilitation anchored on zygomatic implants. The ORIS acronym is used to name four specific criteria to systematically describe the outcome of zygomatic implant rehabilitation: offset measurement as evaluation of prosthetic positioning; rhino-sinus status report based on a comparison of presurgical and postsurgical cone beam computed tomography in addition to a clinical questionnaire; infection permanence as evaluation of soft tissue status; and stability report, accepting as success some mobility until dis-osseointegration signs appear. Based on these criteria, the assessment of five possible conditions when evaluating zygomatic implants is possible.

Little Insights from Big Data: Cerebrospinal Fluid Leak After Skull Base Surgery and the Limitations of Database Research

Cerebrospinal fluid (CSF) leak is a frustrating complication of skull base surgery. Published methodologies using national surgical databases to assess CSF leak have not accounted for variability between skull base operations. Our goal was to attempt the development of a novel framework for adapting big data techniques to skull base surgery and assess the reliability of corresponding data manipulations. A retrospective nested case-control analysis was performed using patients from the National Surgical Quality Improvement Program (NSQIP) registry, 2012-2015. Current Procedural Terminology and International Classification of Diseases, Ninth Revision codes identified possible skull base operations, which were systematically grouped by anatomic location. Meningioma, schwannoma, pituitary adenoma, and trigeminal neuralgia (TN) were included. Of 2918 patients, 84 (2.9%) were readmitted/reoperated on within 30 days for CSF leak. Operations involving the anterior fossa, both middle/posterior fossas in 1 approach, or the orbitocranial zygomatic approach were significantly associated with CSF leak, as were schwannomas and meningiomas in any location (8.5%, 3.1%, 10.2%, 4.1%, and 3.0%; all P < 0.0001). Multivariate analysis of only middle/posterior fossa lesions identified schwannoma (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.3-5.6; P= 0.008), TN (OR, 5.4; 95% CI, 2-14.7; P= 0.008), chronic obstructive pulmonary disease (OR, 3.9; 95% CI, 1.1-14; P= 0.03), and increased operative time (OR, 4.0; 95% CI, 1.7-9.5; P= 0.009) as significant CSF leak risk factors. Based on NSQIP data analyzed using a rational skull base/anatomic framework, risk factors for postoperative CSF leak include chronic obstructive pulmonary disease, operative time, anterior fossa meningioma, and middle/posterior fossa schwannoma or TN. Although databases such as NSQIP can be extensively manipulated to generate surrogate results that may provide limited insight, applications beyond their design should be approached carefully.

Early post-operative outcomes using trans zygomatic approach for the treatment of sphenoid wing meningiomas

Early post-operative outcomes using trans zygomatic approach for the treatment of sphenoid wing meningiomas

Microsurgical management of benign lesions interior to the cavernous sinus: A case series.

Background:Benign lesion interior to the cavernous sinus (CS) is very rare.Objective:In this series we found nonneoplastic lymphatic aggregation and osteoclastoma inside the CS which is very rare and probably not reported in literature. One interesting postoperative complaint of feeling of tickling down of warm water under the skin forehead was found in the patient of inflammatory disease of CS which is not reported in literature. Here we also describe our experiences of microsurgical management of series of benign lesions inside the CS.Materials and Methods:Benign mass originated from the content of CS or inner side of walls of CS, confirmed peroperatively were included in this series. Prospectively recorded data of microsurgical management was retrogradely studied.Results:Total number of patient was 12. Patient's age range was 30–60 years. Follow-up range was 60 months to 19 months. Three was nonneoplastic lesion (tuberculosis, inflammatory and nonneoplastic lymphoid infiltration). Among the 9 neoplastic lesions, two hemangiomas, two meningiomas, three 6th nerve schwannomas, one osteoclastoma and one epidermoid tumor. Middle cranial fossa-subtemporal extradural approach was used in 9 cases and in two cases extended middle fossa zygomatic approach. New postoperative 3rd nerve palsy developed in 5 cases all recovered completely except one. In seven patients 6th nerve palsy developed after operation; only one recovered. Postoperatively simultaneous 3rd, 4th and 6th nerve palsy developed in four cases. One interesting postoperative complaint of feeling of tickling down of warm water under the skin of left sided forehead was found in the patient of inflammatory disease of CS. Mortality was nil. Total resection was done in 9 cases. There was no recurrence till last follow-up.Conclusion:Though decision for microsurgical removal of such lesions is not straight forward. Probably microsurgery is the best option in treating such benign lesions though it may associate with some permanent cranial nerve palsy.

Orbital Abducens Nerve Schwannoma: A Case Report and Review of the Literature

Intraorbital schwannoma is a rare tumor which accounts for about 1–2% of all neoplasms of the orbit. Orbital schwannomas most commonly arise from the sensory branches of the trigeminal nerve. On the other hand, intraorbital abducens nerve schwannomas are extremely rare, with a search of the English literature identifying only four cases of intraorbital abducens nerve schwannoma. This is the 5th reported case of an orbital schwannoma arising from the terminal branch of the abducens nerve to the lateral rectus muscle. We report a case of an intraorbital abducens nerve schwannoma in a 51-year-old man with no signs of neurofibromatosis. The tumor was totally excised with functional preservation of the nerve by a zygomatic approach with lateral orbitotomy. With knowledge of these anatomic features, total removal of the tumor with preservation of the abducens nerve function might be possible.

Cranio-Orbital Pretemporal Skull Base Approach to Sellar/Juxtasellar Tumors

Cranio-orbital zygomatic approach has become an increasingly popular approach in the past two to three decades, enabling us to resect complex lesions in the area of sella turcica, suprasellar, and juxtasellar compartments including the cavernous sinus compartment. Radical tumor resection has been increasingly achieved while preserving and improving neurological function. Further development of pretemporal transcavernous skull base approach enhanced multidirectional access to these complex skull base areas. To achieve proficiency in this approach, prolonged training in skull base laboratories is necessary.

The effectiveness of neurolytic block of sphenopalatine ganglion using zygomatic approach for the management of trigeminal neuropathy

This study was performed to present the outcomes of trigeminal neuropathy management with the application of neurolytic block of sphenopalatine ganglion. This type of procedure is used in cases where pain is not well controlled with medical treatment. Twenty patients were treated with sphenopalatine ganglion neurolysis after their response to pharmacological management was not satisfactory. Significant pain relief was experienced by all but one patient and they were able to reduce or stop their pain medication. The time of pain relief was between a few months and 9 years during the study period. Number of procedures implemented varied as some of the patients have been under the care of our Pain Clinic for as long as 18 years, satisfied with this type of management and willing to have the procedure repeated if necessary. It appears that neurolytic block of sphenopalatine ganglion is effective enough and may be an option worth further consideration in battling the pain associated with trigeminal neuropathy.

Improved subtemporal approach and frontotemporal-zygomatic arch subtemporal approach in resection of cavernous sinus tumors: a clinical comparative study

Objective To compare the efficacy of the improved subtemporal approach and traditional frontotemporal-zygomatic arch subtemporal approach in resection of cavernous sinus tumors. Methods The clinical data of two groups of patients were analyzed retrospectively. There were 26 patients in an improved subtemporal approach (that is preauricular straight incision preserving zygomatic arch) group (group A). There were 14 females and 12 males, and 9 patients had meningioma, and 17 had trigeminal neurinoma. There were 22 patients in a traditional frontotemporal-zygomatic arch subtemporal approach group (group B). There were 13 females and 9 males, 8 patients had meningioma and 14 had trigeminal neurinoma. The incidence of total resection rate, cranial nerve complications of postoperative lateral wall of cavernous sinus in the patients of both groups were compared, and they were followed up regularly after procedure. Results There was no significant difference in the complete resection rate and the incidence of complications of the cranial nerves between the two groups; however, preserving the zygomatic arch subtemporal approach, the time of craniotomy was shortened significantly. The incidences of postoperative temporal branch injury of facial nerve and temporal muscle atrophy were reduced significantly. Conclusions Preauricular straight incision subtemporal approach can fully expose the cavernous sinus and preserve zygomatic arch. The surgery trauma and complications are less. It is a good choice for the removal of tumors in cavernous sinus areas. Key words: Cavernous sinus; Brain neoplasms; Subtemporal approach

Technical Note: Usage of an Ultrasonic Knife to Perform Key Osteotomies in a Cranio-Orbital Zygomatic Approach

Introduction: The Cranio-Orbital Zygomatic (COZ) approach is a commonly used approach for intra- and extradural lesions of the anterior and middle skull base, as well as lesions of the basilar artery. Traditionally, osteotomies of the supraorbital foramen, zygomatic arch, and superior-lateral orbit are made to complete this approach. Tools previously used for these osteotomies include the gigli saw, osteotome, and a B1 bit on a Midas Rex drill without a footplate. Here, we report the first reported experience making osteotomies for a COZ approach using an ultrasonic irrigating knife (Stryker Sonopet sonicontrol knife), which has a single-side seriated-edge blade with a blunt tip.

Reshaping the zygomatic complex: A "small step" in frontotemporal craniotomy and a "big leap" in exposure.

Pterional or fronto-temporal craniotomy, developed by Prof. M. G. Yasargil, is among the most familiar skull base surgery techniques. The cranio-orbito zygomatic (COZ) approach evolved to address the significant limitations of the pterional exposure in excising some parasellar lesions. Although extremely versatile, the COZ technique involves extensive dissection of the cranio-facial soft tissue and reconstruction towards the end of the procedure. The zygomatic reshaping is a minor modification of the pterional approach, which enhances the exposure possible through the classical approach and often circumvents the need for an orbito-zygomatic osteotomy. To demonstrate the technique of reshaping of the zygomatic complex for an optimum surgical exposure and cosmetic results. Between April 2013 and December 2014, 8 patients with various middle and anterior skull base lesions were operated using this technique. These patients form the clinical material for this study. The clinical details, radiological images and follow-up data of these patients were collected for this clinical series. No mortality or significant morbidity were noted in this series. The post-operative cosmetic results were also acceptable. A quick and easy modification of the classical pterional approach through zygomatic reshaping has the potential to provide a significantly enhanced surgical exposure for parasellar lesions. Using this approach, it might be possible to avoid an extensive orbito-zygomatic osteotomy in suitable lesions.

Transfacial Surgical Approaches to Secure Wide Exposure of the Skull Base

BackgroundTreatment of skull base tumors is challenging due to limited access and presence of important neurovascular structures nearby. The success of a complete tumor resection depends on the extent of tumor exposure and secure field of view. While these tumors are often removed by transcranial endoscopic access, transfacial approach is sometimes required depending on the location and size of the tumor. This study describes various transfacial approaches in patients undergoing skull base tumor resection.MethodsFrom March to November 2013, 15 patients underwent skull base tumor resection via transfacial accesses at a tertiary institution. Data were reviewed for patient demographics, type of access used, completeness of tumor resection, surgical outcome, and postoperative complications.ResultsTwo clivus tumor patients underwent transmaxillary approach; three tuberculum- sellae and suprasellar-hypothalamus tumor patients underwent transbasal approach; three clinoid and retrobulbar intraconal orbital tumor patients underwent orbitozygomatic approach; and seven petroclival-area, pons, cavernous sinus, and lateral-sphenoid-wing tumor patients underwent zygomatic approach. In all cases, the upper and lower margins of the tumor were visible. Complete tumor removal consisted of 10 cases, and partial tumor removal in 5. There were no immediate major complications observed for the transfacial portion of the operations. The overall cosmetic results were satisfactory.ConclusionPlastic surgeons can use various transfacial approaches according to the location and size of skull base tumors to secure a sufficient field of view for neurosurgeons.

Surgical treatment of spheno - orbital meningiomas: a clinical review of 18 cases

Objective To investigate the effect and follow - up outcome of transcranial approach for spheno - orbital meningiomas.Method Eighteen cases of spheno - orbital meningiomas were removed through different transcranial approaches including frontal - temporal ( pterional and modified pterional ) approach ( 15 cases),orbital -zygomatic approach( 2 cases) and orbital -zygomatic combined with extended transbifrontal approach( 1 case).The involved sphenoid wing and peri -orbit bone were removed to prevent recurrence.The superior orbital fissure and optic canal were decompressed.The visual function evaluation was performed.The extent of tumor resection was judged by intraoperative finding and postoperative image examination.Results The extent of tumor resection:2 cases were Simpson Grade Ⅰ,6 Grade Ⅱ,8 Grade Ⅲ and 2 Grade Ⅳ.After surgery,proptosis was improved in all patients.Visual function was improved in 13 cases.There was no operation - related death.Tumor recurrence was found in 2 cases.Conclusions Adequate exposure of tumor and bony decompression of related cranial nerves could be achieved from appropriate transcranial approaches,thus could relieve clinical symptoms such as proptosis,visual function disturbance and ocular motor malfunction.Complete surgical resection is difficult to be achieved because of involvement of orbital apex,superior orbital fissure and cavernous sinus. Key words: Meningioma; Microsurgery; Clinical